Method of making holes in the earth



(.111 mmwmm July 23, 1963 R. c. BALDWIN 3,098,641

METHOD OF MAKING HOLES IN THE EARTH Filed Nov. 28, 1960 2 Sheets-Sheet 1flgliff I; A 3' 2' BI 4| F/G.3 8'

INVENTOR c c RONALD c. aA pw/m WM HIS A T RNEY July 23, 1963 R. c.BALDWIN 3,093,641

METHOD OF MAKING HOLES IN THE EARTH Filed Nov. 28, 1960 2 Sheets-Sheet 2FIG. /0

INVENTOR RO/VAL D 6. BALDWIN m HIS TTORNEY been set free by the blast.

United States Patent 3,098,641 METHOD OF MAKING HOLES IN THE EARTHRonald C. Baldwin, Hillsdale, N.J., assignor to Ingersoll- Rand Company,New York, N.Y., a corporation of New Jersey Filed Nov. 28, 1960, Ser.No. 71,937 4 Claims. (Cl. 262-4) This invention relates to a method ofmaking holes in the earth and is primarily concerned with a method ofmaking a hole in a bed of rock.

More particularly the invention is concerned with a method whichcoordinates the performance of the various functions required to make arelatively large hole in a bed of rock.

In making these types of holes, several functions are required to beperformed. For example, when a hole is to be made in a bed of rock, itis necessary to drill a series of blasting bores in which explosives maybe inserted for blasting the rock. After the blasting occurs, it isnecessary to remove the loosened rock which has This is usuallyaccomplished by a powered digging machine having a scoop in the frontwhich scoops up the loosened rock and deposits it in a bucket. A craneor other lifting device is used for lifting the bucket out of the holeand the loosened rock is dumped at the side of the hole or into truckswhere it may be carried away. The removal of the loosened rock by thesemachines is known as mucking and the machines are known as muckers. Asthe hole is formed, it may be necessary to set steel along the verticalsides of the hole and also to line these sides with concrete.

The invention relates to a method for coordinating all of the abovefunctions to obtain maximum efliciency of rock removal per unit of time.This is accomplished by removing the rock in such a way that the bottomsurface of the hole is maintained in the shape of a spiral path with thespiral path starting and finishing at a vertical face. By maintainingthis spiral bottom during the progress of the digging of the hole, it ispossible to derive many advantages relating to the coordination of thevarious functions necessary to make the hole. The shape of the bottom ofthe hole is maintained as a spiral path until the depth of the holedesired has been reached, at which time, the bottom of the hole can bemade level.

In the past it has been the practice to drill a series of blasting boresuniformly to a certain depth depending on the depth of rock desired tobe loosened by the blast. The bores would be spaced uniformly around thebottom of the hole within the particular configuration of the hole to bemade. In this previously known method, all the equipment would beremoved from the hole before detonation of the explosives since theentire bottom of the hole was blasted and equipment left there would bedamaged by the blast.

This known method had many disadvantages, one of the major ones beingthat all of the equipment would have to be removed from the hole duringeach blasting operation and then returned to the hole after the blastinghas been completed. Also as the equipment was returned to the hole aftera blast, it would be placed on a pile of loose rock which was loosenedby the blast which would hinder the performance of the succeedingoperations which were necessary to continue on with the hole. Forexample, it was diflicult for the muckers to ride on and dig into such apile of loose rock. Also drilling could not be commenced until theloosened rock had been removed from the hole. f

This invention eliminates these disadvantages by providing an efficientmethod for performing all the operations simultaneously. V

Accordingly, an object of this invention is to provide an improvedmethod of making a hole in the earth.

Another object of this invention is to provide a method of making a holein the earth in which the bottom of the hole is maintained in thegeneral form of a spiral path during the progress of removing materialfrom the hole.

Another object of this invention is to provide a method whereby thefunctions necessary to form the hole may be accomplished simultaneouslywithout interruption except during blasting.

Another object is to provide a continuous grade at the bottom of thehole whereby the muckers dig downgrade against a solid bottom at alltimes. 7

Another object is to provide a free face parallel to the blast holes towhich all blasting may be accomplished.

The foregoing and other objects of this invention will be obvious fromthe descriptions and drawings wherein:

FIGURE 1 is a perspective view of the bottom of the hole at one stage ofits formation.

FIGURE 2 is a plan view of the hole with various points on thecircumference designated by letters.

FIGURE 3 is a graphic representation of the circumference of the holelaid out as a straight line with the depths of the hole indicated atvarious points on its circumference.

FIGURE 4 is similar to FIGURE 3 except the depths of hole at anotherstage of its formation are indicated.

'FIGURES 5-8 are plan views of the hole during various stages of itsformation.

FIGURE 9 is a cross sectional view of the hole in FIGURE 8 taken alongline 99.

FIGURE 10 is a plan view of the hole showing possible shapes of thevertical face.

In the present invention the bottom surface of the hole 10 is maintainedin the form of a spiral path 12. Necessarily the starting point of thespiral path must be at a different elevation than its termination. Thisdifference in elevation determines the height of the vertical face 13whereby the spiral path commences at the upper edge 14 of the verticalface 13 and the terminates at the lower edge 15 of the vertical face.The bottom of the hole is maintained generally with the particular shapeshown in FIGURE 1 at all times during the progress of the excavation.The method of maintaining this particular shaped bottom will behereinafter described.

FIGURE 2 shows a plan view of the hole 10 with the circumferenceindicated at 16 while FIGURES 3 and 4 show the circumference 16 laid outas a straight line for the purposes of this description. Thecircumference 16 in FIGURE 2 is equal in length to the straight line 16in FIGURES 3 and 4. The vertical lines in FIGURES 3 and 4 indicate thedepth of the hole at the circumference at different stages of itsformation. The spiral surface at the bottom of the hole graphicallytraces out on the circumferential wall of the hole a spiral path whichcommences at X1. The depth at the circumference gradually increases asthe spiral is traced from X1 to A1 as indicated by the length of thevertical lines A1 and B1 in FIGURE 3. For the purposes of thisillustration, eight feet has been selected as the depth to he traveledin making one complete revolution of the spiral. The depth of the holeat the circumference gradually increases as the spiral path is tracedfrom A1 to G1. As the spiral further continues, it returns to itsoriginal circumferential point X1, X2. However, the depth at X2 is now 8foot but since the spiral started out at the point X1 with an elevationof zero, there is a difference in depth of eight foot which correspondsto the height of the vertical face 13 shown in FIGURE 1.

FIGURE 4 illustrates the various depths of the hole as a secondrevolution of the spiral path is traced out. During the secondrevolution, the shape of the spiral is main- 3 tained by removing aconstant depth of rock (in this case 8 feet as shown in FIGURE 4). Thebottom of the hole at the circumference after the second revolution hasbeen completed is designated by subscripts 2. Thus at A2 the depth ofhole at the circumference will be 9 feet. The depth at point B2 will be10 feet as indicated by B2. The depth increases at the circumferenceuntil the second spiral path is traced out back to the originating pointX1, X2, X3. However, this second spiral started out at an elevation of 8feet indicated at X2 whereas the termination of the spiral is at a depthof 16 feet indicated as X3. Thus the vertical face 13 still remains. Thethird revolution and fourth revolution and so on continue until theproper depth of the hole is reached. Thus it can be seen that the bottomof the hole is maintained at a slope at all times and that a verticalface is always present.

The coordination and performance of the various functions for makingthis hole in the shape and manner above described will now be explainedin detail. For the purposes of this illustration the bottom of the holehas been divided into four sectors, each having a designated area forperforming a specific function. However, it is to be understood thatalthough the drawings and following description apply to four sectors,any number of sectors may be used as required. Also the shape of eachsector may be varied as required.

In the bottom of the hole, while sector 20, which is adjacent to thevertical face 13, is being drilled with blasting bores 25 forexplosives, muckers may be used to remove the broken rock loosened froma previous explosion in another sector 23 which is also adjacent thevertical face 13. Simultaneously steel and concrete may be set at thecircumferential edge of the hole in sectors 21 and 22. The muckers digthe loosened rock from sector 23 and dump it into a bucket which ishoisted out of the hole. All of these operations and any other necessaryoperations may be accomplished simultaneously.

After the blasting bores 25 have been drilled in sector it becomesnecessary to detonate the explosives. During the blasting it will benecessary to interrupt the other functions being formed in other sectorsof the hole. However, the equipment being used in the other sectors suchas the muckers and drilling equipment do not have to be removed from thehole since only a portion of the hole is to be blasted as indicated bythe sector 20. Thus it is possible to leave the equipment in the holewith a minimum of protection. The blasting is then commenced by firstdetonating a section 26 of the sector 20 immediately adjacent thevertical face 13 thus breaking and ejecting material from the face 13 toprovide a swell space in section 26. After section 26 has beendetonated, section 27 will be detonated, and the loosened rock insection 26 will not hinder the effectiveness of the blasting in section27 due to the swell space in section 26. Similarly sections 28 and 29are detonated in that order. This series of detonations may beaccomplished electrically at a time delay sequence. In this way eachsection is detonated against a muck pile, therefore providing efiicientuse of the explosive and also reducing flying rock. Four sections 26 to29 have been shown for the purposes of this illustration but it is to beunderstood that any number of sections may be used and blasted asrequired. Also the size and spacing of the blasting bores may be variedas required for proper fragmentation.

After the explosion has occurred, there remains a vertical face I13, asindicated in 'FIGURE 6. The sector area 20, which has just been blasted,now becomes the mucking sector as shown in FIGURE 6. Since the muckingoperation was going on in sector 23 While the drilling was going on insector 20, the operation may be timed such that the mucking in sector 23will be completed at about the same time that the drilling in sector 20is completed. Thus after the blasting of sector 20, the muckers canproceed from sector 23 to sector 20 and commence the mucking operationwhile the drilling crew can proceed from sector go to sector 21 tocommence drilling again.

Also the ground support crew, who were previously placing the steel andconcrete on the walls of sectors 21, 22, would advance to sectors 22, 23as indicated in FIGURE 6. Thus once again all the operations may beperformed simultaneously.

After drilling is completed in section 21, the mucking is finished insector 20 and the ground support crew is finished in sector 22, 23, theequipment in the hole is placed to one side and section 21 is blasted.This system will be repeated and the operation will advance as shown inFIGS. 7 and 8 until each crew returns to the starting point. At thispoint, the hole has increased a depth equal to the height of the face 13and the whole procedure commences once again and proceeds until the holeis finished.

The timing and coordination of these operations may be varied asdesired. *For example, the blasting could be timed so that it wouldoccur at lunch period while the men would be out of the hole or it couldoccur when the shift was changing. In this way, there will be a minimumof down time while blasting.

Holes may or may not be concrete lined. In some cases, concrete will bepoured or sprayed to form a liner and this could also fit into the cycleof operation. For example, in FIGURE 5 the steel may be set in sector 21while the concrete is set in sector 22.

As the first section 26 of each sector 20, 21, 22, 23 is blasted, a muckpile left adjacent to the vertical face 13 serves as a barrier tominimize flying rock from the blast.

It will be noted that with the above method, all phases of operationproceed at a continuous downgrade. For example, if the diameter of thehole was 60 feet and the height of the vertical face was 8 feet, thegrade at the circumference of the hole at the outer edge would beapproximately 4.2%. Thus, the muckers would be digging on a 4.2% gradeagainst a solid bottom. The height of the face 13 is limited by thegrade maintained at the bottom of the hole.

The vertical face against which the blasting is done is not necessarilya straight line, but may be modified to any type configuration asillustrated in FIGURE 10. The straight 'face used in the previousdescription is indicated at 13. However, configurations designated as 30or 31 may be used as desired.

Also a sump (not shown) may be formed at the center of the hole.

The above described method may be used on any type of earth formation.Although the hole 10 is shown in the shape of a circle, it may be anytype configuration.

It is understood that the foregoing description is illustrative of apreferred embodiment of this invention and the scope of the invention isnot to be limited thereto, but is to be determined by the appendedclaims.

I claim:

1. A method of making a hole in a bed of rock by forming the bottom ofthe hole in the shape of a spiral surface terminating in a generallyvertical face, drilling 'a series of blasting bores at the elevatedportion of the spiral surface, placing explosives in said blastingbores, detonating said explosives in a predetermined delay sequence suchthat the explosives adjacent said vertical face are first detonated,removing a portion of the rock loosened by said explosion, andproceeding along a spiral path to form the hole.

2. A method of making a hole in the earth comprising the steps offorming a series of blasting bores in one sector of the hole such thatthe blasting of said bores will cause to be formed in the bottom of thehole a generally spiral surface, placing explosives in said blastingbores, detonating said explosives, removing a portion of the earthloosened thereby and simultaneously drilling a second series of blastingbores such that the blasting of said second series of bores will causeto be formed in the bottom of the hole a generally spiral surface toform a continuation of said first spiral surface, placing explosives insaid second series of blasting bores, detonating said explosives andproceeding in a similar manner along a spiral surface to form the hole.

3. A method of excavating a large vertical hole in the earth of a sizesufiiciently large enough to contain a plurality of men and machineswhich can simultaneously perform drilling and mucking operations indifferent sectors of the floor of the hole, said method comprising:initially excavating a hole to form a vertical radial wall surfaceextending substantially radially between the vertical axis and thecircumference of the hole and to form a floor extending downwardlyspinally about the vertical axis of the hole from the top edge of saidvertical radial wall surface to the bottom edge of the vertical radialwall surface; extending said spiral floor deeper by excavating a sectorof the upper portion of the spiral floor adjacent said vertical radialwall surface to form a new vertical radial wall surface lying at adifferent circumferential angle from the first vertical radial wallsurface said floor extension step being performed by simultaneouslydrilling the upper portion of the spiral floor adjacent the verticalradial wall surface and mucking the portion of the hole over the lowerportion of the spiral floor adjacent the vertical radial wall surface,thereafter locating explosives in the previously drilled upper portionof the spiral floor and blasting that portion of the 'hole floor, andrepeating said simultaneous drilling and mucking operations with the newmucking step being carried out on the previously blasted portion of thefloor and the drilling step being carried out on another sector of theupper portion of the spiral floor; and continuing to repeat said floorextension step until the hole reaches the desired depth.

4. The method of claim 3 wherein: the vertical radial Wall surfaceproduced by said steps is an irregular nonuniform surface, as opposed tobeing a plane surface.

References Cited in the file of this patent UNITED STATES PATENTS1,202,928 Wallace Oct. 31, 1916 1,833,369 ORourke NOV. 24, 19312,591,233 Browne Apr. 1, 1952

1. A METHOD OF MAKING A HOLE IN A BED OF ROCK BY FORMING THE BOTTOM OFTHE HOLE IN THE SHAPE OF A SPIRAL SURFACE TERMINATING IN A GENERALLYVERICAL FACE, DRILLING A SERIES OF BLASTING BORES AT THE ELEVATEDPORTION OF THE SPIRAL SURFACE, PLACING EXPLOSIVES IN SAID BLASTINGBORES, DETONATING SAID EXPLOSIVE IN A PREDETERMINED DELAY SEQUENCE SUCHTHAT THE EXPLOSIVE ADJACENT SAID VERTICAL FACE ARE FIRST DETONATED,REMOVING A PORTION OF THE ROCK LOOSENED BY SAID EXPLOSION, ANDPROCEEDING ALONG A SPIRAL PATH TO FORM THE HOLE.